Internal-combustion engine



E. T. KERSHAW.

INTERNAL COMBUSTION ENGINE.

APPLICATION HLED MAY 21. 1919.

1,337,077. Patented Apr. 13, 1920.

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In w WIIII/ E. T. KERSHAW.

INIERNAL COMBUSTION ENGINE.

APPLICATION FILE Q MAY 21, 1.919.-

Patented Apr. 13, 1920. 3 SHEETS-SHEET 3- MUM grwc/wtoo VVV Em zKew/wUNITED STATES PATENT OFFICE.

l EDWIN T. KERSHAW; OF DENVER, COLORADO, ASSIGNOR TO THE HUNTER GASENGINE AND DEVELOPMENT: COMPANY, A CORPORATION OF COLORADO.

INTEitlEAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Apr. 13, 1920.

Application filed May 21, 1919. Se'rial No. 298,793.

useful Improvements in Internal-Combustion Engines; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to internal combustion engines particularly ofthe twostroke cycle type.

It is one of'theobjects of the present invention to improve internalcombustion engines of the type having a hollow or tubular piston inwhich there is arranged a complementary head or closure member betweenwhich and the top of the piston there is designed to be indrawn,compressed and then expressed into the combustion chamber of the enginea suitable fuel or combustible mixture and to provide for the support ofsuch complementary head through the open end of the piston. It is one ofthe important objects of the present invention to provide an adjustablereciprocating "compression or abutment member within the piston, wherebythe combustible fuel may be brought to any desired degree of preliminarycompression, which degree obviously may vary according to the uses andoperating conditions of the engine.

It is also one of the principal objects of this invention to provide aconstruction whereby a maximum amount of fuel, con- 'sidering the sizeof the engine, may be drawn into the preliminary compression chamber andthere compressed for discharge into the combustion chamber.

Therefore with these and other objects in view as will become manifestto those versed in the art, the invention consists in the construction,combination, and details and elements of the parts as more particularlydescribed in the following specification relative to the illustratedembodiment of the engine in the drawings in which Figure 1 is a central,longitudinal section through one type and conventional form of gasengine. r

Fig. 2 is a similar section taken on a plane at right angles to theplane of Fig. 1, and

Fig. 3 is a cross section on line 3--3 of Fig. 1 through the lower endof the piston on the line of the wrist pin.

Fig. 4 is an enlarged view partly in elevation and partly in section ofFig. 1 and of. slightly modified form to illustrate the means ofadjusting the internal head and eccentric on the crank shaft.

Fig. 5 is a fragmentary end elevation of a portion of Fig. 4.

In the illustrated adaptation of the engine there is shown a convenientform of a headed cylinder 2 resting on a crank case 3 in which is journaled a crank 6 connected by a connecting rod 7 to a wrist pin 8mounted in diametrically opposed bosses 9 formed in or attached to thelower end of a tubular or cylindrical piston 10. The upper end of thispiston is preferably closed by a removable cap or end member 11permitting the insertion and removal of an interior, preferablycup-shaped abutment or compression member or head 12, between which andthe cap 11 of the piston there is formed a chamber in which fuel may becompressed previously to its admission into the combustion chamber 13.The cylinder 2, the piston 10 and head 12 (when the sides therefore arehigh enough to require itas shown in Fig. 1) are provided withregistrable inlet ports 14, 15 and 16 respectively, for the induction ofa suitable fuel from any source and these elements (including member 12when its sides are sufliciently high to require it) are provided alsowith registrable ports generally indicated at 16 and of the compressedfuel from between the piston and the compression member when gree ofcompression of the gaseous fuel and furthermore a feature of theinvention resides in the provision of means for varym the reciprocationof this compression hea As here shown the compression member 12 whichpermit the escape is secured to the upper ends of operating rods 18whose lower portions are passe through apertures or guide ways 19,formed therefor in the bosses 9 of the piston 10. The lower ends of therods 18 are pivotally connected in the presentcase at 20 to eccentricstraps 21 operating on suitable eccentrics 22, secured or formed on theends of the corresponding shaft adjacent to the crank arms 6. Preferablythe eccentrics are secured on the crank shaft 4 in such manner as toprovide for their adjustment and thus to vary the degree of suction andcompression ofthe gaseous fuel between the "compression head 12 and thecap 11 of the piston when these two are in their most distant andclosest relative positions respectively during the operation of themotor after the parts have been adjusted as may be desired as determinedbythe nature of the use of the engine and also by its normal opcratingconditions.

It will be evident from the drawings and the foregoing description thatthe present invention makes possible a shortening of the piston andcylinder of the engine without decreasing the maximum or increasing theminimum ,sizes of the preliminary compres- S1011 space.

It will also be evident that while the foregoing description refers tothe admission of combustible fuel into the preliminary compressionspace, this construction may be as readily used with heavy fuels wherethe fuel is injected into compressed air in the combustion chamber, theair alone (instead of the combustible mixture) being subjected topreliminary compression.

While I have shown the invention in the present case as embodiedin anengine of only one cylinder and its piston, it is obvious that multipleunits may be employed and further that various other modifications,alterations and changes within the spirit of the invention may beresortedto within the scope of the appended claims.

Should the reciprocation of the head 12 be found undesirable orunnecessary in engines constructed for any particular use, it will beevident that the reciprocation may be eliminated by omitting theeccentrics and mounting the supporting rods 18 on any suitable bearingon the shaft 4 or upon any other suitable support within the crank case,thus retaining the advantages of supporting the head 12 through the openend of the piston without causing reciprocation thereof.

The means for adjusting the internal head and eccentric on shaft areillustrated in Figs. 4 and 5 and consist of a hearing or collar 26slidably mounted upon rod 18 and relatively affixed to rod 18 by a setscrew 27 at predetermined positions, and a cap screw 24 in eccentric 22adapted to engage suitable holes 25 in the crank shaft and to interlocksaid eccentric 22 to said crank shaft in predetermined position.

l/Vhat I claim is 1. An internal combustion engine of the two-strokecycle type, having a cylinder, a hollow piston reciprocable therein, anabutment head fitted in the piston, each of said parts having coordinateinlet ports to register at one position thereof, and means for adjustingthe relative position of the head in the piston to change the degree ofcompression of the fuel previously to its being admitted to thecombustion chamber of the engine 2. An internal combustion engine of thetwo-stroke cycle type, having a cylinder, a hollow piston reciprocabletherein, an abutment head fitted in the piston, each of said partshaving coordinate inlet ports to register at one position thereof, andmeans for adjusting the relative position of the head in the piston tochange the degree of compression of the fuel previously to its beingadmitted to the combustion chamber of the engine and for reciprocatingthe head.

3. An internal combustion engine of the two-stroke cycle type, having acylinder, a hollow'piston reciprocable therein, an abutment head fittedin the piston, said parts having registerable inlet ports andregisterable outlet ports for the included chamber, and means adjustablyconnected to the engine shaft for reciprocating the abutment head in thepiston to compress the fuel previously to its admission to' thecombustion chamber.

l. Aninternal combustion engine of the two-stroke cycle type, having acylinder, a hollow piston reciprocable therein, an abutment head fittedin the piston, said parts having registerable inlet ports andregisterable outlet por'ts for the included chamber, andmeans connectedto the engine shaft for reciprocating the abutment head in the piston to.compress the fuel previously to its admission to the combustionchamber, the lower end of the piston having guides, said means includingrods running in the guides, and eccentrics on the shaft and connected tothe rods.

'5. An internal combustion engine of the two-stroke cycle type, having acylinder, a hollow piston reciprocable therein, said parts havingcoordinate inlet ports to register at one position thereof, an abutmenthead fitted in the piston, and means for adjusting the relative positionof the head in the piston to change the degree of compression of thefuel previous to its admission to the combustion chamber of the engine.

6. An internal combustion engine of the two-stroke cycle type, having acylinder, a hollow piston reciprocable therein, said parts havingcoordinateinlet ports to register at one position thereof, an abutmenthead fit- 130 ted in the piston, means connected to the engine shaft forreciprocating the abutment head Within the piston, and means foradjusting the position and reciprocation of the head in the piston.

In an internal combustion engine of two-stroke cycle type having acylinder With 1 a combustion chamber and a hollow piston operativetherein and a complementary member Within the piston to form apreliminary compression chamber within' the piston, adjustable means forsupporting said member through the open end of the piston.

' In testimony whereof I affix my signature.

EDWIN T. KERSHAVV.

